Beseech the Mirror Psst, hey you
Its other card types (such as artifact) and supertypes (such as legendary), if any, will remain unchanged
The previous rules were last released in 2013 (For those curious about how those went, I recommend you check out Arks article here.) But, finally, new rules have arrived, clearing up a lot of questions we all have been having
If youre running a deck that can get quite a few monsters out at once, then Id recommend putting this card straight into the extra deck
There are many prior examples of such thematic reliance, often ending in gimmicky unplayableness
It is also why black is the most common colour alongside blue in legacy and vintage where you need to have some interaction with spells and their potential to be cast so as to not get run over by broken things